One Hidden Reason for Why Velocity’s Up

There’s no hiding from it — baseballs in the major leagues are being pitched faster than ever before, on average. I mean, we don’t have all that much of a record, but the trend is blatantly obvious over the past 10 or 15 years, and it stands to reason it extends ever back. A few years ago, this was a really interesting observation. Now, it’s something everyone already knows. Pitchers throw harder than they used to. That’s a given. Seemingly every bullpen now has an arm or three who would’ve been a certified flamethrower a decade ago.

Why is this happening? It’s important to try to understand the reasons. There are a lot of ideas out there, many of them valid. There’s a belief that, in general, teams are increasingly obsessed with velocity. And bullpens are being used more aggressively, with relievers throwing harder than starters. Newer training techniques are getting more out of young pitchers, so pitchers also just arrive throwing harder. You’ve got teenagers throwing harder, and teams looking for powerful arms and promising bodies — as a consequence, between 2002 – 2004, rookie starters threw their fastballs a hair under 90. The last three years, that average has gone up to 92. Why the increased velocity? “Youth” is a common response.

It’s definitely a big part of the answer. It’s not all of it. I think there’s something else happening, and it can allow us to link a number of this offseason’s free agents.

There was something I noticed when I was researching and writing up a handful of guys. In each case it was interesting, individually, but I think it’s also interesting as part of a potential pattern. More recently, Ian Kennedy‘s stuff has played up. The same can be said of Mike Leake. The same can also be said of J.A. Happ.

Aging curves exist for almost everything. Our basic idea of how fastball velocity ages is that it peaks very early — maybe even when a pitcher is a rookie. Then begins the gradual decline, with the loss of a mile per hour every few years. It makes enough sense; we’re all pretty fresh in our early 20s. As pitchers get older, they put more wear and tear on their bodies, and that saps some potential. The hope is that the pitchers compensate by improving their repertoires or command.

I decided to look at something simple. I identified starting pitchers who threw at least 200 innings somewhere between 2005 – 2014. Then I narrowed to those who also started at least a few times in 2015, and I looked at their average fastball velocities. Of course, overall, velocity was down for the pitchers this past season, relative to before. But at the very top of the list, you get Brandon McCarthy, whose fastball was almost three ticks harder in 2015. If you look down the list a little bit, you see Happ at +1.3mph. You see Leake, at +1.1. You see Kennedy, at +1.1. You see Rich Hill, at +1.0. You also see Mike Pelfrey, just below +1.0. Those are five free-agent starters, all of them signed, and not only have they not lost velocity — they’ve gained it. They’ve bucked the usual aging curve, and they’ve kept themselves relevant.

It’s not just limited to free agents. McCarthy wasn’t a free agent. Chris Sale throws harder than he used to. Jake Arrieta, too, as well as Nathan Eovaldi. Also Cole Hamels, and Carlos Carrasco, and Tanner Roark, and…in your head, when you think about a pitcher aging, you might think of someone more like Jered Weaver, whose fastball went and replaced itself with Mark Buehrle‘s fastball when Weaver wasn’t looking. Ubaldo Jimenez has lost a lot of zip, and so have Justin Masterson and CC Sabathia, and so on. There are still pitchers who age normally, or even quickly. But the aging curve is by no means universal.

As another little test, I looked at starters who appeared as rookies between 2002 – 2004. I averaged their fastballs, and then I averaged the fastballs of those who were still starting five years later. They lost an average of 0.54mph, with a median of -0.70. Then I did the same thing for starters who appeared as rookies between 2009 – 2011. They lost an average of 0.18mph, with a median of 0.00. It’s small, even if it’s real, but it somewhat supports the idea that pitchers are better able to preserve their velocity in the majors, if not improve it.

It’s not an easy thing to track. I’ve been thinking about this for days, and even now you can tell I haven’t figured out the best way to write about it. But the sense I get is our idea of velocity aging curves is maybe a little outdated. People have had no trouble crediting improved training techniques for increasing velocity among young players. But now we’ve also seen examples of better techniques increasing velocity among established players. And for those who don’t gain life, many have still been able to keep it from declining. I remember reading about how the Rays developed a series of shoulder exercises that helped James Shields add two ticks. David Price also added a couple ticks with the same organization. Clayton Kershaw hasn’t really lost anything despite surpassing 1,600 career innings. Now I’m just picking examples off the top of my head, but I trust you know what I’m getting at.

I’m not an expert in this stuff. I know very little about physical training and biomechanics. Thankfully, there are experts, with teams or consulting with players, and I can just pick through their accomplishments. When people have talked about the increase in Tommy John surgeries, they’ve also frequently referred to the apparent decline in shoulder surgeries. That suggests a broad focus on strengthening the shoulder, which would come with velocity benefits. The elbow will still give out whenever it feels like it — look at McCarthy, or look at Homer Bailey, who also had a velocity uptick before the injury. But I’m thinking that fastballs just don’t deteriorate that much. Not given the proper training, which seems easier than ever to find.

Left to do its own thing, the body will throw a baseball less forcefully over time. Body parts age, and they grow weaker. There’s evidence that pitchers are getting better about combating this effect, both anecdotal and statistical. So you have pitchers preserving their fastballs, and you have some other pitchers even improving their fastballs, after reaching the major leagues. It makes you wonder about longevity — as long as the elbow holds out, pitchers could conceivably last longer, which maybe helps explain why the Royals were comfortable guaranteeing five years to Ian Kennedy. Or maybe not. It’s just an idea.

Velocity is up in the game for any number of reasons, and it doesn’t have to all be about the new youth. A critical piece is the hard-throwing new guys. But you also have to keep in mind the old guys. Their fastballs don’t just go away. Not always, not if they don’t let them.



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Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.


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Pale Hose
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Pale Hose
4 months 8 days ago

Maybe the big velocity losers are washing out of the league quicker, leaving the neutral/gainers.

Nathaniel Dawson
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Nathaniel Dawson
4 months 8 days ago

Why wouldn’t that have been happening in the past as well?

ice_hawk10
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ice_hawk10
4 months 7 days ago

i would think the league has become more competitive from a talent perspective? thus older, declining pitchers dont hang around as long as they used to because there are so many young guns waiting to take their jobs.

Anonymous
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Anonymous
4 months 7 days ago

We miss you, Livan Hernandez.

Not you, Jamie Moyer. You know what you did.

Nathaniel Dawson
Member
Nathaniel Dawson
4 months 7 days ago

Major League Baseball has always been competitive from a talent perspective. That hasn’t changed, it’s pretty much always been that way for 150 years. Teams have always wanted the best players playing for them. If pitchers that are losing velocity can’t remain good enough to pitch in the majors in the current era, how is that any different than in the past? Haven’t there always been “young guns” waiting in the wings to take over when a current pitcher starts to lose effectiveness?

If loss of velocity results in poorer performance, teams are going to look to other pitchers. That’s been going on forever. That doesn’t explain why many pitchers recently seem to be losing less velocity than in the past.

Although to be true, “in the past” really only extends to about a decade or so ago with any reliable measurement that we have.

descender
Member
descender
4 months 8 days ago

How about this… As league wide plate discipline declines (I can only assume), pitchers can get away with blowing pitches past people that better contact hitters would have caught up to in the past?

dl80
Member
dl80
4 months 8 days ago

I like this theory. Guys like Kennedy, Happ, Leake, McCarthy are throwing harder, but they aren’t really any more effective. I’m wondering if they are just throwing pitchers harder because a) the strike zone is bigger and b) velocity gets paid.

So command and control be damned.

troybruno
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Member
troybruno
4 months 8 days ago

Are you suggesting that they are sacrificing spin rate / horizontal movement or some other factor for velocity? If not, I’m not sure you’ve solved anything here… If so, that would be very interesting.

Also, I believe that plate discipline (measured by o-swing) has gotten better, no? Are you referring to o-contact?

dl80
Member
dl80
4 months 8 days ago

Since 2005, Zone% has fallen from 54% to 45%.

FStrike% is up from 59% to 61%

But Contact% is down from 81% to 79% and sStrike% is up from 8.8% to 9.9%.

And fastball velocity has climbed from 90 to 92 mph.

So it looks to me like pitchers are raring back and throwing with more effort. They are aiming in the zone on the first pitch but are then throwing more out of the zone.

This could be a result of learning the dramatic difference of 0-1 vs 1-0 or it could be a result of hitters who tend to be more passive on the first pitch?

And perhaps due to the increased velocity, hitters are making less contact.

So here’s a descriptive example:

2005: Pitcher Bob faces Hitter Mike. Bob nibbles a bit on his first pitch and throws around 90 mph. Then he continues to throw in the zone a lot throughout the at bat. Mike makes a lot of contact.

2015: Bob throws 92 mph and comes right at Mike on the first pitch. After getting it to 0-1, he proceeds to throw more out of the zone. Mike makes less contact.

This is overly dramatic and really overstates the differences, especially in FStrike%. But the real question is: is the naturally higher velocity causing Bob to be more aggressive, knowing he can get away with more mistakes and get Mike to chase more out of the zone? Or is Bob raring back and throwing with more effort so that he can do the things above, knowing they will likely be more effective?

I think it’s possible that everyone is throwing harder (meaning with more effort) from high school on up because that’s how you get drafted and get paid. I think it’s possible that this is also increasing the TJ surgeries.

dl80
Member
dl80
4 months 8 days ago

Also, o-swing% has actually gotten dramatically worse, from 20.3% in 2005 to 31.3% in 2015.

The question is, is it the increased velocity giving hitters less time to recognize whether a pitch is going to be a ball?

SomaDaydream
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SomaDaydream
4 months 8 days ago

Is the percentage of innings thrown by older pitchers on the decline?

If we were to do a weighted average age of pitchers based on how many innings they throw (or how many pitches they throw), would we see a downward trend?

SomaDaydream
Member
SomaDaydream
4 months 8 days ago

I was too curious and knew it’d be simple (if a little tedious) to answer this myself.

Going back to 2002 (the first year we have individual pitch data on Fangraphs), the average age by year weighted by number of pitches thrown-
2015 – 28.24325152
2014 – 28.38661426
2013 – 28.19479629
2012 – 28.18389783
2011 – 28.15848972
2010 – 28.13551558
2009 – 28.1185268
2008 – 28.33906427
2007 – 28.46922099
2006 – 28.54552751
2005 – 28.92764471
2004 – 28.86238685
2003 – 28.47384156
2002 – 28.50829477

I then did some quick and dumb linear regressions. There’s something more than just age going on, but the average age of pitchers is lower than it used to be.

I’m a fan of this site, here are my graphs.

free-range turducken
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free-range turducken
4 months 8 days ago

Rounding age to the nearest hundred-millionth is a nice touch. Accurate to within less than half a second.

SomaDaydream
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SomaDaydream
4 months 8 days ago

Lmao. I was just copying and pasting from excel, quick and dirty work with an utter disregard for significant figures.

Johnston
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Member
Johnston
4 months 7 days ago

David, what’s your conclusion?

wily mo
Member
4 months 8 days ago

i was hoping this was going to be about the new planet

Johnston
Member
Member
Johnston
4 months 7 days ago

And I was hoping that the new planet would be named Planet Ten.

Lord John Whorfin: “Where are we going?”
The Red Lectroids: “Planet Ten!”
Lord John Whorfin: “When?”
The Red Lectroids: “Real soon!”

williamnyy
Member
4 months 8 days ago

Two reasons I suspect that may be contributing factors are more specialization (i.e., pitchers with big arms throwing fewer innings, making them more fresh) and more scientific means of recording velocity. Regarding the latter, I wonder if some of the increase might just be the result of more accurate measurement.

dl80
Member
dl80
4 months 8 days ago

That might explain the 92.4 mph Pitchf/x finds in 2015 vs. the 91.1 in 2007. But how does it explain the 92.4 in 2015 vs. the 91.7 in 2011?

I don’t think we’ve suddenly gotten better at measurement from 2011 to 2015.

Anonymous
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Anonymous
4 months 7 days ago

A lot of that is Aroldis Chapman.

CJSportsNut
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CJSportsNut
4 months 8 days ago

Was the shoulder the weak spot previously and the cause of the decline in velocity in years past? Has strengthening the shoulder prevented the loss of velocity and the shoulder injuries, but also eliminated a limiter of sorts on the UCL? More shoulders are now stronger than their elbows can handle?

I like the idea that hitters change pitchers too. Its a very natural selection type of argument. What works vs your adversary is what is selected.

evo34
Member
evo34
4 months 8 days ago

Your first couple of tests (measuring rel. velo of pitchers who did not drop out of the league by year x) suffer from survivorship bias. There’s a reasonable chance the vets that are still pitching are doing so because they are the outliers who do not age normally — i.e., it’s not evidence that most pitchers are aging differently now.

Paul22
Member
Paul22
4 months 7 days ago

Some of those guys listed with increased velocities had injuries.

Others have embarked on shoulder strengthening programs. In McCarthy’s case that led to TJS in 2016 after the velocity bump .

In 2002-2004 there was no steroid testing. 5 years hence many of those SP’ers were off the juice, and subject to a greater velocity decline than those who came up into MLB with steroid testing already in place. Also, there was no pitch f/x in 2002-2004 but there was 5 years later, so perhaps the different measurement methods account for the larger velocity drop

As pointed out by others, there may also be some survivor bias at play here.

Also, we can’t rule out chemicals; Toradol, peptides, HGH (testing has begun only recently ) all may reduce velocity decline as pitchers age and wear and tear develops, if indeed one exists.

I think I would need to see a more convincing presentation of data to be convinced the age related velocity decline is a thing of the past

As for the issue of pitchers throwing harder than in the past, it just seems to me that their are fewer short pitchers than in years past. However, MLB height-weight data is so unreliable I would not trust any study. That said, a quick check of the height of top 20 FIP leaders among qualified starters in 2015 and 2012 show only 10% in 2015 are under 6 ft 2 inches while there were 30% of them in 2002. The reduction in shorter pitchers from the leaders is worth looking into.

Do taller pitchers throw harder or have less of an age related velocity decline?

Johnston
Member
Member
Johnston
4 months 7 days ago

This sort of thing is fascinating to me and articles like this are why I read Fangraphs.

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